The Lions face a winless North Melbourne at Etihad Stadium on Sunday and the depth of their on-ball division will be tested, with Jared Polec yesterday ruled out for six weeks with an ankle injury.

Polec's absence further depletes a group deprived of Claye Beams last week by a season-ending knee injury.

Lions great Simon Black is on the comeback trail from a knee injury, but is at least a week or two away from a return to the seniors.

Redden said it was up to the Lions midfield to step up against the Kangaroos, who have lost to the last three premiers - Collingwood, Geelong and Sydney.

"We need to bring our A-game," Redden said.

"North Melbourne have a quality midfield so it is going to take a big effort from us.

"(Andrew) Swallow is a great clearance player and so is Jack Ziebell. Daniel Wells is dangerous and (Ryan) Bastinac is a great runner.

"They are a young midfield just like us and they will be hungry for a win."

Redden's form has mirrored that of Brisbane's fortunes.

He was well below his best against the Western Bulldogs and Adelaide but hit back with 26 disposals and team-high counts of nine clearances and nine tackles against the Suns in a two-point win on Saturday.

"It (the Q Clash) would have been my best game for the year. But that wouldn't be hard," Redden said.

"I had two pretty average games to start the year but I found some form last week by focusing on the defensive side of my game and running hard.

"Overall as a midfield we did improve against the Gold Coast, but we've still got a lot of work to do."

Brisbane forward Rohan Bewick said the Lions needed to focus on beating teams such as North Melbourne if the Lions were serious about contending for the top eight.

"They've (North Melbourne) played three good teams so we are not counting them as a 0-3 team," he said.

Coach Brad Scott took the blame for the Roos' third straight third-quarter fadeout in losing to Sydney last Saturday, but captain Swallow insists it is shared burden.

The Kangaroos led Sydney by 14 points at halftime but conceded 11 goals to one in the third term.

"The third quarter is not the players' fault. I've got to go back and review myself very closely to make sure I did what was necessary to stem the flow," Scott said post-match.

But Swallow said Scott was trying to take the focus off the players, who have conceded 22 goals to five in the three third-quarters this season. - with Brett Stubbs